1. Field of the Invention
This invention relates to well tools and more particularly to guides for guiding well tools into telescoping relationship with other well tools downhole.
2. Description of the Prior Art
Oftentimes it becomes necessary to lower a well tool into a well on a pipe string and insert such well tool in the bore of another well tool already in the well. For instance, a packer seal nipple might be lowered on a string of well tubing for installation in the bore of a well packer which was installed in the well earlier. In another instance, a fishing tool might be run in the well on a fishing pipe string for insertion in the bore of a portion of pipe string (fish) which has been, through mishap or inadvertence, lost in the well bore.
Under good conditions little difficulty is encountered in inserting the well tool downhole. On the other hand, great difficulty is encountered in making the insertion if the well tools to be mated are not or cannot be provided with suitable and efficient guide surfaces. But, probably the most trouble of this nature develops in well bores which are crooked or slanted. Even if a well bore were as perfectly straight and as vertical as a plumbline, a pipe string suspended therein would not remain centered, but would almost assuredly be in contact with the wall of the well bore at most places and particularly at the lower end of such pipe string. Often a plurality of pipe strings will be run simultaneously into a well as when completing multiple wells for producing from multiple zones. Such multiple pipe strings should definitely not be rotated in the well, for to do so would almost assuredly result in damage thereto and very likely require replacement of at least a part of the equipment at great expense and loss of time.
Tubular well tools, such as packer seal nipples and tail pipes cannot always be provided with a bullet-nosed guide for easy entry, but must be open ended, for instance, for running tools therethrough. Such open ended tools are subject to lodge atop the packer or fish. This is especially true of the packer which because of its structure is centered in the well. When the seal nipple approaches the packer and is sliding along the wall of the well bore, it is almost sure to lodge.
In the past, such well tools have had a guide surface formed thereon by cutting off the lower end of the tool at a slant of about 45 degrees. Such slanted guide surfaces are often termed "muleshoes." A common form of guide surface is provided by cutting off a portion of the bottom of the well tool in such manner that the cutting plane (slanted about 45 degrees) intersects the longitudinal axis at or very near the bottom of the well tool. This latter form is particularly suited for those cases where the running-in pipe string can be rotated should the well tool lodge atop the packer, or the like. Rotation of the guide will soon bring the slanted guide surface around to the point of interference and will cam or guide the well tool past the shoulder upon which it has been lodged so that the well tool will readily enter the bore of the packer, or the like.
Examples of well tool guides with slanted guide surfaces appear in the Composite Catalog of Oilfield Equipment and Services, 1970-71 Edition, at pages 3800, 3805, and 3806. Such guides must be rotated by turning the running-in pipe string when they lodge in the well as before explained.
Applicants are not aware of any well tool guide which is rotated by merely manipulating the running-in pipe string vertically, that is, by repeatedly picking up the pipe string when the guide lodges and then lowering it again until the guide either lodges or enters the bore sought to be entered.
Applicants are aware of certain prior art showings of devices which translate longitudinal reciprocal movement into rotational movement. Examples of such structures are found in the following U.S. Pat. Nos.:
2,739,654 PA1 3,735,827 PA1 3,054,454 PA1 3,900,074 PA1 3,664,427
U.S. Pat. No. 2,739,645 to M. M. Kinley et al. discloses a pin and cam slot arrangement for causing a longitudinally directed jarring impact to impart a rotational force for loosening a threaded connection in a well.
U.S. Pat. No. 3,054,454 to R. T. Evans discloses a pin and slot arrangement on a running tool to aid in setting a bridge plug, or the like, in a well. (See FIGS. 2, 3, and 4.) Reciprocal longitudinal movement of an arbor having a slot running thereabout in a zig-zag manner relative to a pin engaged in the slot provides rotational movement necessary to operate the J-slot on the bridge plug so that it can be set in place in the well bore.
U.S. Pat. No. 3,664,427 to T. M. Deaton discloses a pin and slot arrangement in which a valve having a zig-zag slot encircling its outer surface is reciprocable within a housing having a pin engaged in the zig-zag slot. As the valve is reciprocated, the pin progresses around the zig-zag slot and alternately allows the valve to go on seat and be locked off seat.
U.S. Pat. No. 3,735,827 to William O. Berryman discloses a pin and slot arrangement for controlling the action of a downhole fishing jar.
U.S. Pat. No. 3,900,074 to George W. Lee discloses a sand removal tool including telescoping sections adapted for relative longitudinal movement accomplished by manipulation of a cable swivelly attached thereto by which the tool is lowered into a well. The inner telescoping member has a bit on its lower end while near its upper end it has a pair of lugs which project outwardly into engagement with a pair of opposed helical grooves inside the outer member. Slacking off on the cable causes the outer member to rotate as it descends, and when its lower end pacts against an external shoulder on the bit attached to the inner member, the bit is caused to rotate due to the rotational inertia of the outer member, the impact shoulders having clutch means to limit slippage therebetween. Thus, the entire tool is caused to rotate.
None of the prior art patents discussed above solve the problem of guiding well tools into bores such as packer bores, receptacles, and the like. The well tool guides with muleshoes or slanted guide surfaces such as those shown in the Composite Catalog, mentioned hereinabove, work well provided the pipe string on which they are run can be rotated.
The present invention overcomes the problems and shortcomings discussed above by providing a well tool guide for guiding well tools into the bores of packers, or the like, on which such well tools are likely to lodge and where such well tools, for one reason or another, cannot be rotated by rotating the running-in pipe string from the surface.